Britain is helpless to stopChinafrom backtracking on promises of free elections in Hong Kong, the head of the foreign affairs committee has said, as activists in the city seemed to lose steam in their battle for democracy.

Sir Richard Ottaway spoke after Beijing set out surprisingly conservative terms for the election of Hong Kong's leader in 2017.

While Hong Kongers will each get a vote, the nomination of candidates will be controlled by a 1,200-strong election committee filled by pro-Beijing figures.

"And if you have a committee that is not neutral and is nominating a limited number of candidates, there seems to be a prima facie case that the undertakings given have been breached," he told the BBC.

Sir Richard is leading a parliamentary inquiry into Hong Kong's electoral reforms ? to the irritation of Beijing, which has lambasted the process as "interference" in its domestic politics.